rack-rewrite for yesWWW (require www in url)

production.rb

ExampleApp::Application.configure do
  # Requires rack-rewrite: https://github.com/jtrupiano/rack-rewrite
  config.middleware.insert_before(Rack::Lock, Rack::Rewrite) do
    r301 /.*/, Proc.new {|path, rack_env| "http://www.#{rack_env['SERVER_NAME']}#{path}" }, :if => Proc.new {|rack_env| rack_env['SERVER_NAME'] !~ /www\./i}
  end
  #... the rest of production environment config.
end

Nice work man!